1. Field of the Invention
The present invention relates to a call disconnection method and an exchange executing the same in an ATM (Asynchronous Transfer Mode) network.
2. Description of the Related Art
The ATM is a transfer mode for transferring various broad band and narrow band information, e.g., image, voice, data, etc., and wherein a cell including information having a certain length and a header is transferred.
A number of cells is determined in response to an amount of information. Accordingly, an accounting in the ATM network is decided by the number of cells transmitted through an exchange in the reception side. Namely, the accounting is determined in accordance with the number of cells and the communication distance.
Therefore, by using the above accounting method, when a data cell is not transmitted, if the call is connected, the accounting is not accumulated. Thus, when the burst data which is, for example, used in the data communication is transmitted, even if the data cells are not transmitted for a long time, the call is held during the long time.
In the exchange, whenever the call is held, since a certain frequency band must be secured, the calls exceeding the band wherein the exchange operates cannot be held. For that reason, if some terminal equipment holds a call continuously and does not disconnect the call, in the case of exceeding the band handled by the exchange, when another terminal equipment requests a call, the exchange must reject the request. Thus, a new call cannot be connected.